Papers by Robert F . LaPrade
Arthroscopy: The Journal of Arthroscopic & Related Surgery, 2009
The purpose of this study was to evaluate the results of double-bundle posterior cruciate ligamen... more The purpose of this study was to evaluate the results of double-bundle posterior cruciate ligament (PCL) reconstruction using a non-hardware suspension fixation technique and 8 strands of autogenous hamstring tendons. Methods: Twenty-two cases of isolated chronic PCL rupture were reconstructed arthroscopically with 8 strands of autogenous hamstring tendons in a double-bundle and 4-tunnel manner. Quadruple-stranded semitendinosus tendon graft and quadruple-stranded gracilis tendon graft were used to reconstruct the anterolateral bundle and posteromedial bundle, respectively. The grafts were fixed by use of a non-hardware suspension fixation technique. Results: Nineteen patients were followed up for a minimum of 2 years. Before surgery, 15 patients had a 2ϩ posterior drawer test (PDT) and 4 patients had a 3ϩ PDT. At a minimum of 2 years after surgery, 17 patients (89.5%) had a negative PDT, 1 patient (5.3%) had a 1ϩ PDT, and 1 patient (5.3%) had a 2ϩ PDT. The mean KT-1000 examination results (MEDmetric, San Diego, CA) changed from 9.4 Ϯ 1.8 mm preoperatively to 1.0 Ϯ 1.0 mm postoperatively (P Ͻ .001). The stress radiography results changed from 10.6 Ϯ 2.0 mm preoperatively to 2.0 Ϯ 1.2 mm postoperatively (P Ͻ .001). According to the International Knee Documentation Committee knee examination form, the results were graded as normal in 15 patients (78.9%), nearly normal in 3 patients (15.8%), and abnormal in 1 patient (5.3%). The International Knee Documentation Committee subjective results increased from 65.6 Ϯ 5.1 to 92.1 Ϯ 3.7 (P Ͻ .001), and the Lysholm score increased from 63.5 Ϯ 4.9 to 92.5 Ϯ 4.1 (P Ͻ .001). The Tegner score was 5.1 before surgery and 6.3 at the last follow-up on average. Conclusions: The results of this study showed that arthroscopic double-bundle PCL reconstruction by use of a non-hardware suspension suture fixation technique and 8 strands of autogenous hamstring tendons can yield normal results in 78.9% of patients and nearly normal results in 15.8% at a minimum of 2 years. Level of Evidence: Level IV, therapeutic case series.
The American journal of sports medicine, 2018
The qualitative and quantitative anatomy of the medial patellar stabilizers has been reported; ho... more The qualitative and quantitative anatomy of the medial patellar stabilizers has been reported; however, a quantitative analysis of the anatomic and radiographic attachments of all 4 ligaments relative to anatomic and osseous landmarks, as well as to one another, has yet to be performed. To perform a qualitative and quantitative anatomic and radiographic evaluation of the medial patellofemoral ligament (MPFL), medial patellotibial ligament (MPTL), medial patellomeniscal ligament (MPML), and medial quadriceps tendon femoral ligament (MQTFL) attachment sites, with attention to their relationship to pertinent osseous and soft tissue landmarks. Descriptive laboratory study. Ten nonpaired fresh-frozen human cadaveric knees were dissected, and the MPFL, MPTL, MPML, and MQTFL were identified. A coordinate measuring device quantified the attachment areas of each structure and its relationship to pertinent bony landmarks. Radiographic analysis was performed through ligament attachment sites a...
The American Journal of Sports Medicine, 2017
Background: Revision anterior cruciate ligament reconstruction (ACLR) is becoming increasingly co... more Background: Revision anterior cruciate ligament reconstruction (ACLR) is becoming increasingly common as the number of primary ACLR cases continues to rise. Despite this, there are limited data on the outcomes of revision ACLR and even less information specifically addressing the differences in 1-stage revision reconstruction versus those performed in a 2-stage fashion after primary reconstruction. Purpose: To compare the outcomes, patient satisfaction, and failure rates of 1-stage versus 2-stage revision ACLR. Study Design: Cohort study; Level of evidence, 3. Methods: All patients who underwent revision ACLR between 2010 and 2014 by a single surgeon were collected, and skeletally mature patients over the age of 17 years were included. Patients were excluded if they were skeletally immature; had a previous intra-articular infection in the ipsilateral knee; underwent a prior alignment correction procedure, cartilage repair or transplant procedure, or meniscal allograft transplantatio...
Orthopaedic journal of sports medicine, 2014
Hip endoscopy facilitates the treatment of extra-articular disorders of the proximal femur. Unfor... more Hip endoscopy facilitates the treatment of extra-articular disorders of the proximal femur. Unfortunately, current knowledge of proximal femur anatomy is limited to qualitative descriptions and lacks surgically relevant landmarks. To provide a quantitative and qualitative analysis of proximal femur anatomy in reference to surgically relevant bony landmarks. Descriptive laboratory study. Fourteen cadaveric hemipelvises were dissected. A coordinate measuring device measured dimensions and interrelationships of the gluteal muscles, hip external rotators, pectineus, iliopsoas, and joint capsule in reference to osseous landmarks. The vastus tubercle, superomedial border of the greater trochanter, and femoral head-neck junction were distinct and reliable osseous landmarks. The anteroinferior tip of the vastus tubercle was 17.1 mm (95% CI: 14.5, 19.8 mm) anteroinferior to the center of the gluteus medius lateral insertional footprint and was 22.9 mm (95% CI: 20.1, 25.7 mm) inferolateral to...
Journal of Experimental Orthopaedics, 2014
Background Revision anterior cruciate ligament (ACL) reconstruction requires a precise evaluation... more Background Revision anterior cruciate ligament (ACL) reconstruction requires a precise evaluation of previous tunnel locations and diameters. Enlargement of the tunnels, despite not usually affecting primary reconstruction outcomes, plays an important role in revision ACL management. Three dimensional (3D) computed tomography (CT) models are reported to be the most accurate method for identifying the tunnel position and possible conflicts with a revision tunnel placement. However, the ability of 3D CT to measure the tunnel size is still not proven. The goal of this study was to evaluate the ability of measuring the size of the bone tunnels in ACL reconstructed knees with 3D CT compared to the traditional two dimensional (2D) CT method. Methods Twenty-four patients had CT scans performed immediately following ACL reconstruction surgery. Their femoral tunnels size were measured by a standard 2D CT measurement and then compared with three novel 3D CT measuring methods: the best transve...
Knee Surgery, Sports Traumatology, Arthroscopy, 2014
CI 0.142, 0.238) and negative predictive value was 0.986 (95 % CI 0.967, 0.996). For lateral meni... more CI 0.142, 0.238) and negative predictive value was 0.986 (95 % CI 0.967, 0.996). For lateral meniscus posterior root tears, sensitivity was 0.600 (95 % CI 0.281, 0.860), specificity was 0.903 (95 % CI 0.891, 0.912), positive predictive value was 0.181 (95 % CI 0.085, 0.261) and negative predictive value was 0.984 (95 % CI 0.972, 0.994). Conclusions This study demonstrated moderate sensitivity and specificity of 3 T MRI to detect posterior meniscus root tears. The negative predictive value of 3 T MRI to detect posterior meniscus root tears was high; however, the positive predictive value was low. Sensitivity was higher for medial root tears, indicating a higher risk of missing lateral root tears on MRI. Imaging has an important role in identifying meniscus posterior horn root tears; however, some root tears may not be identified until arthroscopy. Level of evidence Prognostic study (diagnostic), Level II.
Revista Brasileira de Ortopedia (English Edition), 2015
Although injuries to the posterolateral corner of the knee were previously considered to be a rar... more Although injuries to the posterolateral corner of the knee were previously considered to be a rare condition, they have been shown to be present in almost 16% of all knee injuries and are responsible for sustained instability and failure of concomitant reconstructions if not properly recognized. Although also once considered to be the "dark side of the knee", increased knowledge of the posterolateral corner anatomy and biomechanics has led to improved diagnostic ability with better understanding of physical and imaging examinations. The management of posterolateral corner injuries has also evolved and good outcomes have been reported after operative treatment following anatomical reconstruction principles.
The Journal of Bone and Joint Surgery (American), 2008
Background: Objective measures to quantitate the amount of lateral compartment opening for patien... more Background: Objective measures to quantitate the amount of lateral compartment opening for patients with lateral and posterolateral knee injuries have not been well documented. The purpose of the present study was to measure lateral compartment opening secondary to applied varus stresses following posterolateral corner structure sectioning and to develop radiographic guidelines to quantify the amount of lateral compartment gapping seen with these injuries. Methods: Ten nonpaired fresh-frozen cadaver lower extremities were used. Two varus loads, a 12-Nm moment and a clinician-applied varus stress, were applied to the intact knees and after sequential sectioning of the fibular collateral ligament, popliteus tendon, popliteofibular ligament, and anterior and posterior cruciate ligaments to simulate degrees of posterolateral knee and associated combined cruciate ligament injuries. The shortest distance between the most distal subchondral bone surface of the lateral femoral condyle and the corresponding lateral tibial plateau was measured to quantify lateral compartment opening and was analyzed on digital radiographs. Three observers were used to determine interobserver reproducibility and intraobserver repeatability. Results: In the intact knee, the mean lateral compartment gapping due to a 12-Nm moment and a clinician-applied varus stress was 8.9 and 9.7 mm, respectively. Lateral gapping significantly increased by 2.1 and 2.7 mm in association with sectioning of the fibular collateral ligament and by 3.4 and 4.0 mm in knees with a simulated posterolateral corner injury for each respective load-application technique (p < 0.0001 for all comparisons). Intraobserver repeatability was high, with all observers independently obtaining an intraclass correlation coefficient of 0.99, whereas the analysis of interobserver reproducibility demonstrated an intraclass correlation coefficient of 0.97. Conclusions: Measurements with use of current clinical digital imaging systems can be used to quantify the amount of lateral compartment knee opening. Clinicians should suspect an isolated fibular collateral ligament injury if opening on clinician-applied varus stress radiographs increases by approximately 2.7 mm and a grade-III posterolateral corner injury if values increase by approximately 4.0 mm. Clinical Relevance: Varus stress radiographs appear to provide an objective and reproducible measure of lateral compartment gapping that should prove useful for the diagnosis, management, and postoperative follow-up of patients with fibular collateral ligament and posterolateral knee injuries. I njuries to the fibular collateral ligament and other posterolateral corner structures can be difficult to diagnose on physical examination of the knee, especially in the setting of concurrent cruciate ligament injuries. Previous authors have recognized the difficulty of relying solely on physical examination and have sought tools to quantify instability in order to facilitate accurate diagnosis, to facilitate preoperative and postoperative examinations, and to establish values to be used
The Journal of Bone and Joint Surgery (American), 2010
Background: Chronic posterolateral knee injuries often result in substantial patient morbidity an... more Background: Chronic posterolateral knee injuries often result in substantial patient morbidity and functional instability. The clinical stability and functional outcomes following anatomic reconstructions in patients with a chronic posterolateral knee injury have not been determined, to our knowledge. Methods: A two-center outcomes study of sixty-four patients with grade-3 chronic posterolateral instability was performed. The patients were evaluated subjectively with the modified Cincinnati and International Knee Documentation Committee (IKDC) subjective scores and objectively with the IKDC objective score. Results: Eighteen patients had an isolated posterolateral knee reconstruction, and forty-six patients underwent a singlestage multiple-ligament reconstruction that included reconstruction of one or both cruciate ligaments along with the posterolateral knee reconstruction. The average duration of follow-up was 4.3 years. The fifty-four patients who were available for follow-up had an average total Cincinnati score of 65.7 points. A significant improvement was found between the preoperative and postoperative IKDC objective scores for varus opening at 20°, external rotation at 30°, reverse pivot shift, and single-leg hop. Conclusions: An anatomic posterolateral reconstruction resulted in improved clinical outcomes and objective stability for patients with a grade-3 posterolateral knee injury.
The Journal of Bone and Joint Surgery (American), 2007
Background: The orthopaedic literature contains relatively little quantitative information regard... more Background: The orthopaedic literature contains relatively little quantitative information regarding the anatomy of the posterior aspect of the knee. The purpose of the present study was to provide a detailed description of, and to propose a standard nomenclature for, the anatomy of the posterior aspect of the knee. Methods: Detailed dissection of twenty nonpaired, fresh-frozen knees was performed. Posterior knee structures were measured according to length, width, and/or distance to reproducible osseous landmarks. Results: The semimembranosus tendon had eight attachments distal to the main common tendon. The main components were a lateral expansion to the oblique popliteal ligament; a direct arm, which attached to the tibia; and an anterior arm. The oblique popliteal ligament, the largest posterior knee structure, formed a broad fascial sheath over the posterior aspect of the knee and measured 48.0 mm in length and 9.5 mm wide at its medial origin and 16.4 mm wide at its lateral attachment. It had two lateral attachments, one to the meniscofemoral portion of the posterolateral joint capsule and one to the tibia, along the lateral border of the posterior cruciate ligament facet. The semimembranosus also had a distal tibial expansion, which formed a posterior fascial layer over the popliteus muscle. A thickening of the posterior joint capsule, the proximal popliteus capsular expansion, which in this study averaged 40.5 mm in length, connected the posteromedial knee capsule at its attachment at the intercondylar notch to the medial border of the popliteus musculotendinous junction. The plantaris muscle, popliteofibular ligament, fabellofibular ligament, and semimembranosus bursa were present in all specimens. Conclusions: The anatomy of the posterior aspect of the knee is quite complex. This study provides information that can lead to further biomechanical, radiographic imaging, and clinical studies of the importance of these posterior knee structures.
The Journal of Bone and Joint Surgery (American), 2012
There is growing evidence that knee cruciate ligament reconstruction achieves improved results wi... more There is growing evidence that knee cruciate ligament reconstruction achieves improved results with restoration of the native anatomy [1,2]. Despite the recognized importance of anatomic reconstruction tunnel placement, an accurate and reproducible method to guide tunnel placement for posterior cruciate ligament (PCL) reconstructions has not been developed. Arthroscopically pertinent details about the locations of the anterolateral bundle (ALB) and posteromedial bundle (PMB) of the PCL are required to accurately guide anatomic tunnel placement for PCL reconstructions. The purpose of this study was to both qualitatively and quantitatively describe the positions of the ALB and PMB of the PCL relative to arthroscopically relevant osseous and soft-tissue landmarks to improve anatomic PCL reconstruction tunnel placement. Materials and Methods: Dissections were performed and arthroscopically relevant measurements of the ALB, PMB, meniscofemoral ligaments, and pertinent anatomical landmarks were taken on twenty non-paired fresh-frozen human cadaveric knees (average age, 46 years) using a three-dimensional electromagnetic tracking system as described previously [3]. In order to establish interobserver reproducibility of the measurements between the anatomic landmarks and center of the fiber bundles, five of the cadaveric specimens were completely remeasured by a second observer and interobserver interclass correlation coefficients (ICC) were calculated based on the repeated measurements. Results: Qualitative analysis revealed a consistent pattern to the shape of the distal margin of the intercondylar notch. Several points along this margin were identified where the slope of the cartilage immediately changed direction in a consistent and definable manner (Fig. 1). The ALB femoral attachment was located between the articular cartilage and medial intercondylar ridge (MIR), and anterior to the medial bifurcate ridge. The PMB femoral attachment was distal to the medial intercondylar ridge, posterior to the medial bifurcate ridge, and often located between the anterior and posterior meniscofemoral ligaments. The average distance between the ALB and PMB bundle centers was 12.1 mm (+/-1.3). The perpendicular distance from the edge of the medial femoral condyle cartilage to the center of the ALB was 7.9 mm (+/-1.5), while to the center of the PMB it was 8.6 mm (+/-1.9).
The American Journal of Sports Medicine, 2005
Background The individual biomechanical strength properties of the fibular collateral ligament, p... more Background The individual biomechanical strength properties of the fibular collateral ligament, popliteofibular ligament, and popliteus tendon have not been well elucidated by previous studies. To define the necessary strength requirements for a posterolateral knee reconstruction, these properties for the main individual structures of the posterolateral knee need to be defined. Hypothesis The biomechanical failure properties of the fibular collateral ligament, popliteofibular ligament, and popliteus tendon can be determined by cadaveric testing. Study Design Descriptive laboratory study. Methods Each structure was individually isolated in 8 fresh-frozen, nonpaired cadaveric knees and loaded to failure at more than 100%/s. Results The mean ultimate tensile strength of the fibular collateral ligament was 295 N, the popliteofibular ligament was 298 N, and the popliteus tendon was 700 N. The mean cross-sectional areas of these same structures at their midpoints were 11.9 mm2, 17.1 mm2, ...
The American Journal of Sports Medicine, 2004
Background Little information is known about the forces seen on the main individual structures of... more Background Little information is known about the forces seen on the main individual structures of the posterolateral knee to applied loads. This information is needed to determine which structures should be reconstructed and also the relative strengths needed for reconstruction grafts. Purpose To determine in vitro forces in the fibular collateral ligament, popliteofibular ligament, and popliteus tendon for various posterolateral knee loading conditions. Study Design Cadaveric study. Results The fibular collateral ligament was loaded in varus, internal rotation, and external rotation. The highest amount of force seen on the fibular collateral ligament was at 0° of knee flexion with external rotation, with the mean load response to external rotation significantly less at 90°. Fibular collateral ligament varus load response at 0°, 30°, and 60° was fairly constant, with a significant decrease at 90° compared to 30° of knee flexion. The popliteus tendon and popliteofibular ligament were...
The American Journal of Sports Medicine, 2009
Background Further knee surgery after proximal tibial osteotomies has been reported to have a mor... more Background Further knee surgery after proximal tibial osteotomies has been reported to have a more difficult surgical exposure due to decreased patellar height after the osteotomy. Although a decrease in patellar height has been reported for closing-wedge proximal tibial osteotomies, it has not been widely verified among opening-wedge procedures. Hypothesis A significant decrease in patellar height would result after opening-wedge proximal tibial osteotomies and a postoperative change in tibial slope would also result, depending on the medial tibial plate position, which would affect patellar height. Study Design Case series; Level of evidence, 4. Methods Patients (n = 129) who underwent opening-wedge proximal tibial osteotomies (n = 130) were prospectively followed. Patellar height was calculated for preoperative lateral knee radiographs, and postoperatively at 2 weeks and 3 and 6 months. The Insall-Salvati, Blackburne-Peel, and Caton-Deschamps indices and a modified Miura and Kawa...
Knee Surgery, Sports Traumatology, Arthroscopy, 2011
Purpose The purpose of our study was to determine if sectioning the canine fibular collateral lig... more Purpose The purpose of our study was to determine if sectioning the canine fibular collateral ligament, popliteus tendon, and popliteofibular ligament would result in residual posterolateral instability and produce measureable evidence of early-onset arthritis on ultra-high field MRI. Methods The fibular collateral ligament, popliteus tendon, and popliteofibular ligament were surgically sectioned in six canines. Six months postoperatively, both limbs were biomechanically tested involving 3.25 Nm varus and 1.25 Nm internal and external rotation torques at 28.5°(mean full extension), 60°, and 90°of flexion. A 7.0-tesla MRI scanner acquired T 1q-weighted images, and relaxation time constants were calculated. Results Compared to the non-operative knees, varus angulation significantly increased by 2.0°, 8.0°, and 12.4°i n the operative knees at full extension, 60°flexion, and 90°fl exion, respectively. External rotation was significantly increased by 8.1°at full extension, 12.2°at 60°, and 8.2°at 90°. Internal rotation was significantly increased by 9.1°at full extension and 12.4°at 60°. T 1q MRI mapping revealed a significant increase in relaxation times in the medial compartment of the surgical knees compared to controls. Conclusion This study validated that grade III surgically created posterolateral knee injuries do not heal and that the canine knee developed early-onset changes of the medial compartment, indicative of early-onset osteoarthritis, developed in the operative knees. Keywords Posterolateral knee injuries Á Canine Á Osteoarthritis Á Knee instability Á 7 Tesla MRI Á T 1q mapping Winner of the ''Best Poster Award-ESSKA 2010, Oslo Norway''.
Thedevelopment of an in vivo animalmodel of posterolateral knee instability is desired for devisi... more Thedevelopment of an in vivo animalmodel of posterolateral knee instability is desired for devising effective interventions for this injury. Sequential sectioning of the popliteus tendon, lateral collateral ligament, and lateral capsule was done in cadaveric goat knees to create knee joint instability, followed by in vivo studies (Studies 1 and 2) of 7 and 3 months duration, respectively. In Study 1, the popliteus tendon and lateral collateral ligament were sectioned; in Study 2, these structures as well as the lateral joint capsulewere sectioned. Biomechanical testing and histological assessments were done to determine the severity of the instability and the morphological changes. Sectioning the lateral collateral ligament and popliteus tendon (Study 1) resulted in a significant increase in varus instability at 908. Sectioning the lateral collateral ligament, popliteus tendon, and lateral capsule (Study 2) resulted in significant varus instability at 308, 608, and 908, and signific...
The American Journal of Sports Medicine, 2008
Background Stress radiography provides an objective tool to measure posterior knee instability. I... more Background Stress radiography provides an objective tool to measure posterior knee instability. Intraobserver and interobserver reliability has been reported for the Telos device, but it has not been studied using the kneeling technique. Purpose This study was conducted to evaluate the intraobserver and interobserver reliability of measurements made using kneeling stress radiography to quantify posterior knee instability. Study Design Case series (diagnosis); Level of evidence, 4. Methods One hundred thirty-two stress radiographs in 44 patients with suspected posterior knee instability were prospectively taken using the kneeling technique. The amount of posterior displacement on the radiographs was then measured independently by 3 blinded testers (an orthopaedic sports medicine faculty member, an orthopaedic chief resident, and a medical student) on 2 separate occasions. Changes in mean and intraclass correlation coefficients (ICCs) were examined to assess the intraobserver and inte...
Knee osteochondral lesions can be debilitating. Multiple procedures have been used to manage thes... more Knee osteochondral lesions can be debilitating. Multiple procedures have been used to manage these defects. Osteochondral autograft transplantation is one such option. Reported complications include donor-site morbidity, failed osteointegration, size mismatch, and incongruency. In this article, we report a case of graft incongruency of the medial femoral condyle that resulted in a full-thickness "kissing lesion" groove on the opposing medial tibial plateau. In an osteochondral autograft transplantation procedure, proper surgical technique is paramount to prevent placement of a proud autograft and avoid the difficult complication of associated tibial chondral defects.
Arthroscopy Techniques
Increased sagittal plane posterior tibial slope has been identified as a risk factor for primary ... more Increased sagittal plane posterior tibial slope has been identified as a risk factor for primary anterior cruciate ligament reconstruction (ACLR) failure. Although ACLR failure is multifactorial, correction of sagittal plane posterior tibial slope should be evaluated in patients with an ACLR graft rupture. There are limited technical descriptions of proposed decreasing tibial slope osteotomy procedures; therefore, the purpose of this Technical Note is to describe the current senior author's technique of performing an anterior closing wedge proximal tibial osteotomy to decrease sagittal plane tibial slope in patients requiring a revision ACLR.
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Papers by Robert F . LaPrade